Fertilizer Fundamentals: The Best Time to Fertilize

When to Fertilize

So, you’ve read How to Choose a Fertilizer, and How to Apply Fertilizer, but what about when to apply fertilizer?

Depending on what you plan to fertilize, the timing application may differ. For example, it is best practice to apply fertilizer to turfgrass only when it is actively growing. Turf will not absorb any fertilizer when it is dormant.

Dormancy for warm season turfgrasses, such as bermudagrass, St. Augustinegrass, zoysiagrass and bahiagrass begins in mid-October through mid-March or early April. Do not fertilize turfgrass during these months (note: some counties/municipalities have fertilizer black-out dates so call your local UF/IFAS Extension Office for ordinance information specific to your area).

Fertilizing turfgrass during these months can lead to cold damage/death, a waste of money and time, and lead to water pollution. Fertilizers contain nitrogen and phosphorus which cause algal blooms, red tide, fish kills, etc. Whatever is applied to plants, if it is not readily taken up and used by the plant, eventually finds it’s way into water resources due to the nature of our sandy soils and heavy rains which causes runoff.

Proper shelf storage of agriculture-based pesticides and fertilizers. Photo courtesy of Tyler Jones UF/IFAS.

When Do Plants Need Fertilizer?

Fertilizing is not one size fits all. There is not one definitive time that all plants need fertilizer. Truth is, all plants differ in their growing seasons, nutrient requirements, and growth pattern. So, the right time to fertilize is going to be based on the needs of the specific plant.

Also keep in mind that established trees and shrubs do not generally need fertilizer – only young plants that haven’t yet become established need fertilizer. To be certain, use a soil test to determine what, if any, fertilizer is needed by established trees and shrubs.

A homeowner waters her lime tree after spreading citrus fertilizer. Photo courtesy of Cat Wofford UF/IFAS.

You’ll want to match the applications to the plant growth pattern and nutrient demands throughout the season. Meaning, you’ll want to fertilize them when they’re actively growing and hold off when they’re dormant. Regular fertilizer applications keep plants vigorous and productive, but the goal is to give the nutrients to the plant when they are most likely to absorb them.

Too much fertilizer or adding fertilizer at the wrong time can damage and burn plants. In a garden, if you overfertilize tomatoes and beans, you will get lots of pretty green foliage, and little fruit! In the case of fertilizer, more does not equal better!

Read Fertilizing – Maintenance – Landscape plants – Edward F. Gilman – UF/IFAS (ufl.edu) for more fertilizing timing and practices and details for veggie gardens.

Conclusion

So, there you have it – the key to successful fertilization lies in timing it just right. Remember, each plant has its own unique needs and growth patterns, so it’s crucial to match fertilizer applications accordingly. By fertilizing during periods of active growth and avoiding overapplication, you’ll ensure your plants receive the nutrients they need to thrive without risking damage. With the right timing and care, your garden will thrive like never before!

Supervising agent: Dr. Whitney Elmore County Extension Director, Urban Horticulture Agent, and Master Gardener Coordinator

Read more about fertilizers in our Fertilizer Fundamentals series:

Have a question?

If you have any questions about gardening in Central Florida, please contact the UF/IFAS Extension Pasco County at 352-518-0156. For more information on UF/IFAS Extension Pasco County Community Gardens, and how you can join one, visit http://sfyl.ifas.ufl.edu/pasco/.

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